Submarine FAQs

Submarine FAQ

Frequently Asked Questions

Q. How many submarines do we have?

The present complement of submarines within the RN is; 4 in number SSBNs, based at Faslane on the West coast of Scotland, approx. 25 miles from Glasgow, and 11 SSNs split between Faslane and Devonport in Plymouth.

Q. What are the differences between classes of submarines?

"Hunter killer" submarines (designated SSNs by the RN) are designed to pursue and attack enemy submarines and surface ships using torpedoes. They are also able to carry "cruise" missiles for use against shore-based targets. This type of submarine is used to conduct surveillance and intelligence gathering tasks as well as other types of classified operations. Ballistic missile submarines (designated SSBNs) carry long-range nuclear warhead missiles. They roam the oceans of the globe avoiding contact, to ensure that their anonymity is not compromised. The ability to strike at any time has ensured that deterrent value of SSBNs, or "Bombers", has proved effective in preventing attack on the UK.

An SSN is approx. 85 x 10 x 10 metres and weighs in the region of 5000 tons when submerged. An SSBN is larger at 150 x 13 x 12 metres and weighs in excess of 15000 tons. A London double-decker bus is 10 x 5 x 3 metres and weighs about 4 tons

Q. How deep can a submarine go?

A submarine can dive to depths in excess of 250 metres. The actual depth is classified.

Q. How fast can a submarine go?

Modern nuclear submarines can travel at speeds in excess of 25 miles per hour and can maintain this speed indefinitely, so allowing the submarine the ability to go anywhere in the world quickly and quietly.

Q. Where are submarines built?

At the present time all UK submarines are built at Barrow-in-Furness in Cumbria, and over 50% of all UK submarines have been built there. In the past submarines have been built in Birkenhead Merseyside, and on the Clyde in Scotland

Q. Why are submarines painted black?

It helps them to hide. If you were to look down at the sea from above, then it would appear as a dark depth, so it is sensible to paint the submarine a colour that will blend into the background.

Q. What weapons are on a submarine?

Submarines carry torpedoes, cruise missiles and ballistic missiles. Torpedoes are for use against other ships or submarines in time of war. Cruise missiles allow the submarine to target sites that are several hundred miles from the nearest sea. Ballistic missiles can be fired at targets that are many thousands of miles from the sea, and are used as a deterrent, to prevent other countries from waging war on Great Britain.

Q. How many missiles and torpedoes are on a submarine?

The exact amount of missiles and torpedoes carried by UK submarines is classified, however each submarine will carry sufficient weapons to carry out its task.

Q. What types of mission can submarines carry out?

Depending upon whether it is a hunter killer or a missile submarine, a submarine is capable of performing many important tasks. Sea Control (denying the ocean to hostile naval forces through ant-submarine and anti-surface warfare) Anti-Submarine Warfare (detecting and destroying hostile submarines) Anti-Surface Warfare (detecting and destroying hostile surface ships) Strategic Deterrence (launching retaliatory strikes against any nation attacking the UK with nuclear weapons) Landing Special Forces (performing covert infiltration of hostile regions by commando forces) Intelligence, Surveillance, and Reconnaissance (listening for hostile electronic communications and information) Carrier Group Support (providing intelligence and undersea protection for aircraft carriers and their support vessels) Cruise Missile Strike Capability (striking ground targets with conventionally armed warheads)

Q. How long can you stay underwater?

Nuclear Submarines are able to produce their own indefinite supply of air, water and power for driving the submarine forward. It's only limitation for staying submerged is the amount of food on board, or if they sustain a major defect.

Q. How do submarines dive and surface?

To dive or submerge the submarine, valves on the top of the very large ballast tanks are opened. This allows the air in the tanks to escape; at the bottom of the tanks are holes that allow the seawater to flood in. As water is heavier than air, the submarine becomes heavier and therefore sinks in a controlled manner. To surface the submarine, the valves on the top of the ballast tanks are shut, high-pressure air is pumped into the tanks and the water is forced out through the holes at the bottom. The tanks fill with air and "float" the submarine to the surface.

Q. How old is the Commanding Officer on a submarine?

On average the Commanding Officer of a submarine will be between 35 and 45.

Q. How many people are there on a submarine?

Crew size depends on the class or type of submarine, but a typical British submarine would have a crew of around 120 officers and men, which compares to the original crew of the first British submarine that had a crew of 8

Q. What does it look like through the periscope?

Just as is seen in films, there are dashed lines on the eyepiece of a modern periscope, which aid the operative in gauging distances. However, a modern day submarine periscope is much more than just an eye on the outside world. They are more often then not fitted with TV cameras, radio aerials and other electronic gadgets.

Q. How do the crew receive medical attention?

All submarines carry qualified medical ratings and there are standard operating procedures for any medical emergencies that are beyond their skills. If the submarine is operating in areas that make it unsuitable to evacuate casualties, then they will embark a submarine qualified doctor.

Q. What does it feel like to be on a submarine?

Although it is difficult for most people to imagine living on a submarine, challenging submarine living conditions actually build strong fellowship among crewmates. The crew is highly motivated and quickly adapts to the conditions. It is a busy life of watches, work and exercise drills. There are four meal times per day with breakfast, lunch, supper and a midnight meal for the watch changeover. Sleep is taken during the off-watch periods, and submariners soon become adept at dropping off to sleep as soon as their heads touch the pillow. Submarines are normally quieter than their surface counterparts, and tend to be more stable due to the depth. The air is cleaner than the outside air and many submariners notice the strong smell of the ocean when the hatches are opened after a long spell at sea.

Q. What does the crew do in their spare time?

Typically, the submarine day is divided into 4 x 6-hour slots or watches. The majority of the submarine crew is divided into 2 watches, which will spend 6 hours "on-watch" followed by a period of 6 hours "off-watch". This cycle is repeated for the entire time that the submarine is at sea. When "on-watch", the crew will be actively operating their assigned equipment. When "off-watch" the crew will basically eat and sleep. Obviously reading, TV and studying for exams will also take up time. There are also limited facilities for keeping fit, with most submarines carrying an exercise bike, rowing machine and an assortment of free weights.

Q. What do you eat?

Submariners eat everyday food like you would find on any table in a British home. Imagine shopping for 120 men for 6 months and planning every meal in that time! The fresh fruit, vegetables, and dairy products don't last if the submarines programme takes it away from port for any length of time, but the chefs on board have become masters of creativity and invention. Typical meals would be full cooked "English" or cereals for breakfast; filled rolls, burgers or pizza for lunch, and a chicken, pork or mince dish for supper. Every week there will be a "special" menu.

Q. What is sonar?

SONAR (Sound Operated aid to Navigation And Ranging) is the system that provides a submarine with its underwater ears and eyes. It is used to detect other ships and submarines, undersea mountains, and can tell the submarine what is happening in the alien environment around it. There are two types of sonar: Active and Passive. When operating in the Active mode, a submarine will send out a pulse of sound into the water and listen for the echo of that sound to return but this is rarely used. Passive Sonar operates by listening for the sounds emitted by other vessels and then carries out analysis of these sounds to determine the characteristics of that vessel. Skilled passive Sonar operators are able to determine the number of propellers fitted, the number of blades on each propeller, and from this, name the individual class of vessel.

Q. How far away can you hear other ships?

Using sonar it is possible to hear other ships many miles away while underwater. If the other vessel is very noisy then the distance can be in excess of 75 miles. Sonar reception is very dependent on water temperature, other activity in your area and the weather on the surface.